PHOENIX — Max Scherzer allowed three homers Tuesday but compensated by saving the Mets in the middle innings.

For the Mets co-ace that meant battling to get the final out of the fifth inning after the Diamondbacks had tied the game and then returning to pitch a perfect sixth.

Those four outs kept manager Buck Showalter from diving into his bullpen early.

“It was one of Max’s best outings because of what he had to deal with and the way he got through it,” Showalter said after the Mets beat the Diamondbacks 8-5 at Chase Field.

“Max pitching the sixth inning was impressive. That kind of set up the rest of the game for us.”

Two infield hits and two walks had allowed the D’backs to tie it 4-4 in the fifth.

But Scherzer, on his 32nd pitch of the inning, struck out Christian Walker with the bases loaded to prevent further damage.

Corbin Carroll, Walker and Lourdes Gurriel Jr., accounted for the other scoring against Scherzer — each hit a solo homer.

“Solo homers don’t beat you,” Scherzer said. “I was able to go out there and attack and get some runs early and when the game got kind of hairy there in the fifth I was able to get a big strikeout there and not let the game get out of control.”

Scherzer pitched consecutive clunkers against the Braves and Yankees in June but followed with three straight strong outings leading into Tuesday.

A significant factor in his turnaround was locating his slider — a pitch that gave him mixed results against the D’backs.

“It was good and then in the middle innings it kind of got away from me,” Scherzer said.

“I think by the end I kind of fixed it and got it under control.”

Francisco Alvarez delivered the biggest hit, a two-run homer in the seventh that traveled 467 feet to left-center and gave the Mets a 6-4 lead before they tacked on in the eighth and ninth.

Scherzer, who characterized Alvarez’s blast as “awesome,” remains convinced the Mets aren’t finished this season.

“Everybody has got to do their job,” Scherzer said.

“When we play well as a team we all click and we can play with anybody in this league.”